Functional polymer

ABSTRACT

A functional polymer including at least two different types of side chains, having the general formula (1), 
                         
wherein A is an at least monosubstituted alkylene or arylene group; B is an amide, ester or ether group and n is 0 or 1; F is selected from: an ester, secondary amine, amide, ether, thio ether, thio ester, and may be the same or different for the different side chains; D is a side chain intended to reversible bind to a substrate or has a coating function; E is a side chain intended to irreversible bind to a substrate, the side chain E and polymer includes 1 to 10 different side chains D and 1 to 10 different side chains E, but at least one of each, and includes a plurality of each type, whereby the different types of side chains are randomly or regularly distributed in the polymer.

The present invention relates to a functional polymer for coating ofdifferent substrates.

Surface modification is a well-known strategy to modify a material'sphysicochemical properties. Among the various surface treatmentpossibilities, the application of a coating is a simple andstraightforward manner to add new functionalities and properties to abase material.

Ultra-thin polymeric coatings are normally generated according to twodifferent processes. In the bottom-up or grafting-from approach polymersare grown from the surface thanks to polymerization reactions between asurface deposited reactive agent and the monomers present in thesolution where the to be coated materials are dipped in. In the othercase, bottom-down or grafting-to, the previously synthesized moleculesare assembled onto the surface from a liquid or gas phase.

Macromolecules, 43, 2010, 1050-1060 discloses a class of polymers basedon the polycationic poly(L-lysine)-graft-poly(ethylene glycol) copolymer(PLL-g-PEG) with a fraction of the amine-terminated lysine side chainscovalently conjugated to 3,4-dihydroxyphenylacetic acid (DHPAA). Thiscopolymer is shown to adsorb and self-organize as a confluent monolayeron negatively charged titanium oxide surfaces. However, the synthesis ofsaid copolymer is difficult and expensive, also due to the charge in thepolymer backbone. In addition, it is not possible to easily amend theside chains depending on the intended use.

U.S. Pat. No. 8,568,872 discloses a polymer comprising a plurality ofanchoring molecules, in particular polymers comprising catechol sidechains. Due to the absence of another binding group, said polymer is notcompatible with all different substrates. For example a strong bindingwith for example SiO₂ substrates is not possible.

It is therefore an object of the present invention to provide a polymercomprising side chains with different binding affinities to severaltypes of substrates.

The problem is solved by the polymer according to claim 1. Furtherpreferred embodiments are subject of the dependent claims.

The functional polymer according to the present invention comprises atleast two different types of side chains, said polymer having thegeneral formula (1),

whereinA is an at least monosubstituted alkylene or arylene group,B is an amide, an ester or an ether group and n is either 0 or 1,F is selected from the group of an ester, a secondary amine, an amide,an ether, a thio ether, a thio ester, and may be the same or differentfor the different types of side chains,D is a side chain which is intended to reversible bind to a substrate orcarries a coating functionality, and D is selected from the groupconsisting ofa short chain side chain D1 having a linear or branched, substituted orunsubstituted C₁ to C₁₂ alkyl group R_(D1), which optionally comprisesheteroatoms, and which carries a functional group K1;a side chain D2 having a long chain R_(D2) selected from the groupconsisting of polydimethylsiloxanes, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran, carboxymethyldextran, poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide),whereby D2 has no functional end group or side group;a side chain D3 having a long chain R_(D3) selected from the groupconsisting of polydimethylsiloxanes, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran, carboxymethyldextran, poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide) and D3carries at least one functional end or at least one functional sidegroup K3,E is a side chain which is intended to irreversible bind to a substrate,said side chain Ehaving a linear or branched, substituted or unsubstituted C₁ to C₂₀,preferably C₁ to C₁₂ alkyl group R_(E), which optionally comprisesheteroatoms, and carries at least one functional group K4, oris the functional group K4, andthe polymer comprising 1 to 10 different types of side chains D and 1 to10 different types of side chains E, but at least one type of side chainD and at least one type of side chain E, and said polymer comprising aplurality of each type of side chain,whereby the different types of side chains are randomly or regularlydistributed in the polymer.

The backbone unit A in the polymer backbone is an at leastmonosubstituted alkylene or arylene group, preferably it is amonosubstituted alkylene or arylene group, the only substituent beingthe linker group F. Most preferably backbone unit A is a monosubstitutedalkylene group, such as an ethylene, propylene, butylene or pentylenegroup comprising as substituent the linker group F. Good results couldbe obtained when A is an ethylene group. Typically, the polymer backbonecomprises at least 10 units A, preferably at least 50 units, mostpreferably at least 80 units. Generally, a longer polymer backbonecomprises more side chains, which provide the desired functionalitiesand binding behavior and results therefore in a more stable coating ofthe substrate.

Group B designates an optional linker group and may be for example anamide, an ester or an ether group. Said linker group B is arrangedbetween the backbone units A. However, preferably there is no group Bpresent in the polymeric backbone, that is, preferably the integer n is0. That is, each polymer unit A is connected to the adjacent polymerunit A resulting in a polymer backbone -A-A-A-A-. In case the integer nis 1, B is preferably an ether group resulting in a polyether backbone.

The polymer backbone of the polymer according to the present inventionis preferably not charged. In addition, it preferably does not containpolylysine in the backbone.

Since the polymer according to the present invention is preferablyobtained by post-modification of a polymer backbone carrying a reactivegroup, the group F links the side chain D or E to the polymer backbone.The linker group F is formed by reaction of a reactive group G on thepolymer backbone with a reactive group H on the side chain D or E. Saidgroup F is selected from the group of an ester, a secondary amine, anamide, an ether, a thio ether, a thio ester, and may be the same ordifferent for the different types of side chains, which depends on thereactive group H of the side chain, which is intended to be reacted withthe reactive group of the polymer backbone. Preferably, the linker groupF is an amide.

Before carrying out the modification reaction possible reactive groups Gon the polymer backbone are selected from the group consisting ofesters, activated esters, chloro, fluoro, acrylate, methacrylate, NHSesters, epoxides, anhydrides, azides, alkines, and acyltrifluoroborates.The reactive group G may be connected directly to a carbon atom in thepolymer backbone, or a methylene group, an ethylene group or a propylenegroup may be between the carbon atom of the polymer backbone and thereactive group G. Preferably, the reactive group G is connected directlyto a carbon atom in the polymer backbone.

One possible backbone carrying such a reactive group ispoly-(pentafluorophenylacrylate), wherein pFP stands forpentafluorophenyl and is the reactive group G and the backbone unit A isethylene:

D in the functional polymer of formula (1) is a side chain, which isintended to reversible bind to a substrate and/or carries a coatingsfunctionality. The term reversible bonding within the context of thepresent application stands for a weaker interaction such as van derWaals bonding, hydrogen bonding or electrostatic bonding. The termcoating functionality stands for a new physicochemical property providedby the coating which does not belong to the intrinsic property of thesubstrate material.

Side chain D is selected from the group consisting of

a short chain side chain D1 having a linear or branched, substituted orunsubstituted C₁ to C₁₂ alkyl group R_(D1), which optionally comprisesheteroatoms, and which carries at least one functional group K1;

a side chain D2 having a long chain R_(D2) selected from the groupconsisting of polydimethylsiloxanes, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran, carboxymethyldextran, poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide),whereby D2 has no functional end group or side group;a side chain D3 having a long chain R_(D3) selected from the groupconsisting of polydimethylsiloxanes, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran, carboxymethyldextran, poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide) and D3carries at least one functional end or at least one functional sidegroup K3.

Side chain D1 is intended to reversible bind to a substrate, whereasside chains D2 and/or D3 carry a coating functionality.

The functional polymer according to the present invention may comprisedifferent types of side chains D, for example two different types ofshort chain side chains D1, two types of a long chain side chain D2 andone type of long chain side chains D3. Preferably, the functionalpolymer according to the present invention comprises one type of sidechain D1 (for example an alkyl chain comprising a terminal amine), onetype of side chain D2 (for example polyethylene glycol) and optionallyone type of side chain D3 (for example polyethylene glycol comprisingone or more biotin units). Of course, the polymer according to thepresent invention comprises from each type of side chain a plurality ofsaid side chains, which are identical.

E is a side chain, which is intended to irreversible bind to asubstrate. The term irreversible bonding within the context of thepresent application stands for a covalent bonding between the functionalgroup of the side chain and the substrate surface, or for a strongcoordination bond between the functional group and the substratesurface. The side chain E has either a linear or branched, substitutedor unsubstituted C₁ to C₂₀, preferably C₁ to C₂₀ alkyl group R_(E),which optionally comprises heteroatoms and carries at least onefunctional group K4 or it is the functional group K4. In the latter caseno alkyl group R_(E) is present, that is the functional group K is bounddirectly to the reactive group G of the polymeric backbone forming thefunctional group F.

The polymer according to the present invention comprises 1 to 10different types of side chains D and 1 to 10 different types of sidechains E. The expression “type of side chain” stands for one specificside chain, which may be a side chain of class D or a side chain ofclass E.

However, the polymer according to the present invention must compriseone type of side chain D and at least one type of side chain E. That is,at least one type of side chain bonds irreversible to the substrate,whereas at least one type of side chain bonds reversible to thesubstrate and/or carries a coating functionality, which results in aloosely binding and/or in a coating functionality.

The difference between irreversible bonding and reversible bonding isnot only given by the difference in bonding strength, as also theadsorption kinetics leading to a surface interaction is differentbetween the two cases. Physiosorption, that is, the reversible bonding,is considerably faster as there is no activation barrier to overcome.Therefore, the weak-binding, in particular, the weak binding long-rangeinteractions enable good surface spatial organization of the moleculescontaining ionizable groups due to intramolecular charge repulsion. Thisresults in a higher density and controlled organization of the polymeraccording to the present invention due to the stretched conformation ofthe polymer in solution. On the other hand, the covalent binding groupof the at least one other type of side chain shows a lower packingdensity when adsorbed onto the surface. The stability of the binding isstronger thanks the creation of a covalent or coordinativenon-reversible bond. Therefore, the polymer according to the presentinvention is no longer highly influenced by the environmental conditionssuch as the pH of the solution or the ionic strength. The combination ofthe reversible and the irreversible bonding capabilities of the polymeraccording to the present invention results in a unique capability ofoptimal packaging and strong bonding. In addition, the polymer accordingto the present invention has an outstanding compatibility with a givensubstrate. The polymer according to the present invention comprisesseveral chemical functionalities for both tailoring surface adhesion aswell as polymer functionality dependent on its use, such ashydrophilicity, charge, wettability, lubrication, protein resistanceetc. Therefore, the polymer according to the present invention can adoptspontaneously the best polymeric organization for a reproducible,enhanced and simple way to adhere on the substrates of interest, whileexposing its desired functionality to the environmental interface.

The polymer according to the present invention comprises a plurality ofeach type of side chain. Preferably, essentially all (that is more than90%) reactive groups of the polymer backbone result in a linker group Fcomprising a side chain D or E. Most preferably, the amount of linkergroups F is almost equal (more than 90%) to the amounts of groups A inthe backbone.

In the polymer according to the present invention the different types ofside chains are randomly or regularly distributed in the polymer.Preferably, they are randomly distributed in order to have an easiersynthesis and a more homogenous surface distribution.

Preferably, the polymer according to the present invention comprises aside chain D1 in which the functional group K1 is selected from thegroup consisting of amines, carboxy, poly (propylene sulfide) andthioethers.

Preferably, the above mentioned functional group K1 is terminal.Although it is possible that the side chain D1 comprises more than onefunctional group, it comprises preferably only one functional group.

Depending on the reactive group G on the polymer backbone resulting inthe linker group F, the compound which is reacted with the reactivepolymer backbone comprises also an additional functional group H whichis intended to react with the reactive group such as an amine, analcohol or a thiol. The functional group is preferably terminal. Thefollowing scheme shows an illustrative example of a first reaction ofthe polymer backbone with a side chain D1.

The short chain side chain D1 (—R_(D1)—K₁) has a linear or branched, C₁to C₁₂ alkyl group R_(D1), which optionally comprises heteroatoms in thechain and may be substituted or unsubstituted. The starting compound forthe side chain D1 has the following general formulaH—R_(D1)—K₁  (4),whereinH is the functional group, which is intended to react with the reactivegroup G of the polymer backbone resulting in the linker group F,R_(D1) is the linear or branched C₁ to C₁₂ alkyl group, which optionallycomprises heteroatoms in the chain and may be substituted orunsubstituted, andK₁ is a functional group, which will be defined further below.

If R_(D1) is substituted it may comprise 1 to 2 methyl or ethyl groups,halogen atoms or carboxy groups. In addition, the alkyl group R_(D1) maybe linear or branched. Preferably, R_(D1) is a linear, unsubstitutedalkyl chain with 1 to 12 carbon atoms. Most preferably, R_(D1) isselected from the group of methylene, ethylene, propylene, butylene,pentylene, hexylene, heptylene, octylene, nonylene, decylene,undecylene, dodecylene, —(CH₂)—CH(COOH)—, —C(═O)—O—(CH₂)_(n)—; and—C(═O)—NH—(CH₂)_(n)—, wherein n=1 to 8. Most preferably R_(D1) isselected from the group consisting of ethylene, butylene, hexylene andundecylene.

The term amine stands for a primary amine (R_(D1-2)—NH₂), a secondaryamine, such as R_(D1)—₂—NHCH₃, a tertiary amine, such asR_(D1-2)—N(CH₃)₂ or an ammonium such as R_(D1-2)—NH₃ ⁺ orR_(D1-2)—N(CH₃)₃ ⁺, and R_(D1-2) is preferably a linear, unsubstitutedalkyl chain with 1 to 12 carbon atoms. If the functional group in D1 isan amine, D1 is preferably selected from the group of ethyleneamine,propyleneamine, butyleneamine, pentyleneamine, hexyleneamine,heptyleneamine, octyleneamine, nonyleneamine, decyleneamine,undecyleneamine and dodecyleneamine, preferably ethyleneamine,butyleneamine or hexyleneamine and most preferably hexyleneamine. Aminesform in particular good electrostatic bondings to negatively chargedsurfaces, metal oxides, and polymers (in particular activated polymers)and weak coordinative bonds to noble metals.

The term thioether stands for thioethers of the formulaR_(D1-5)—CH₂—S—CH₃, wherein R_(D1-5) is preferably a linear C₁ to C₁₂alkyl. If the functional group in D1 is a thioether, D1 is preferablyselected from the group of methylene thioether, ethylene thioether,propylene thioether, butylene thioether, pentylene thioether, hexylenethioether, heptylene thioether, octylene thioether, nonylene thioether,decylene thioether, undecylene thioether and dodecylene thioether,preferably ethylene thioether, hexylene thioether or undecylenethioether. Thiolethers form in particular good bondings to noble metalsand form van der Waals interactions with hydrophobic substrates. Withinthe context of the present invention thioethers are considered to bindreversible to a substrate.

The term carboxy stands for a COO⁻ residue. Due to the negative chargethe carboxy group forms a weak, long range electrostatic bond onpositively charged surfaces, in particular on metal oxides. If thefunctional group in D1 is a carboxy group (R_(D1-5)—COO⁻), D1 ispreferably selected from the group of ethylene carbonic acid(R_(D1-5)═C₁), propylene carbonic acid (R_(D1-5)═C₂), butylene carbonicacid (R_(D1-5)═C₃), pentylene carbonic acid (R_(D1-5)═C₄), hexylenecarbonic acid (R_(D1-5)═C₅), heptylene carbonic acid (R_(D1-5)═C₆) andoctylene carbonic acid (R_(D1-5)═C₇), nonylene carbonic acid(R_(D1-5)═C₈), decylene carbonic acid (R_(D1-5)═C₉), undecylene carbonicacid (R_(D1-5)═C₁₀) and dodecylene carbonic acid (R_(D1-5)═C₁₁),preferably ethylene carbonic acid or hexylene carbonic acid.

The term poly (propylene sulfide) stands for

wherein i is 1 to 20 and R_(D1-6) between the linker group F and thefunctional group is preferably linear C₁ to C₁₂ alkyl. If the functionalgroup in D1 is a poly (propylene sulfide), D1 is preferably selectedfrom the group of methylene poly (propylene sulfide), ethylene poly(propylene sulfide), propylene poly (propylene sulfide), butylene poly(propylene sulfide), pentylene poly (propylene sulfide), hexylene poly(propylene sulfide), heptylene poly (propylene sulfide), octylene poly(propylene sulfide), nonylene poly (propylene sulfide), decylene poly(propylene sulfide), undecylene poly (propylene sulfide) and dodecylenepoly (propylene sulfide), preferably ethylene poly (propylene sulfide),hexylene poly (propylene sulfide) or undecylene poly (propylenesulfide). Poly (propylene) sulfides form in particular good weakmultisite coordination bondings to noble metals.

Preferably, at least one type of side chain of the functional polymeraccording to the present invention is a long chain side chain D2. D2 ispreferably selected from the group of polydimethylsiloxanes,perfluoroethers, perfluoroalkyls, polyisobutene, polyethylene glycol,polydimethylacrylamide, polyvinylpyrrolidone, polyalkyloxazolines,dextran, carboxymethyl dextran, poly(N-isopropylacrylamide),poly(N-hydroxyethylacrylamide, poly(2-hydroxyethyl methacrylate),poly-hydroxypropylmethacrylate), poly-(methacryloyloxylethylphosphorylcholine), polyalkylene residues having more than 20 carbonatoms, peptide chains, DNA fragments poly-(sulfobetaine methacrylate),polyalkylene residues having more than 20 carbon atoms, peptide chains,DNA fragments and poly-(sulfobetaine acrylamide).

Typically such a “long chain” side chain D2 has a molecular weight of500 Da to 20′000 Da, preferably from 1000 Da to 10′000 Da. Preferably,R_(D2) is selected from the group consisting of polydimethylacrylamide,polyalkyloxazoline and polyethylene and most preferably polyethyleneglycol. Said side chains D2 carry a coating functionality, that is theyhave for example non-fouling properties (in case of for example PEG, PVPand POXA) or provide other functionalities (such as hydrophobicity,oleophobicity in case of PDMS, and fluorinated polymers) to alldifferent substrate types such as metal oxides, glass, polymers, andnoble metals.

Preferably, at least one type of side chain is a long chain side chainD3 (—R_(D3)—K₃). The starting compound for the side chain D3 has thefollowing general formulaH—R_(D3)—K₃  (6),whereinH is the functional group, which is intended to react with the reactivegroup G of the polymer backbone resulting in the linker group F, andR_(D3) is selected from the group consisting of polydimethylsiloxane,perfluoroethers, perfluoroalkyls, polyisobutene, polyethylene glycol,polydimethylacrylamide, polyvinylpyrrolidone, polyalkyloxazolines,dextran, carboxymethyl dextran, poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide, poly(2-hydroxyethyl methacrylate),poly-hydroxypropylmethacrylate), poly-(methacryloyloxylethylphosphorylcholine), poly-(sulfobetaine methacrylate), polyalkyleneresidues having more than 20 carbon atoms, peptide chains, DNA fragmentsand poly-(sulfobetaineacrylamide, andK₃ is the functional group, which will be defined further below. D3comprises preferably only one functional group K3. However, it is alsopossible that is comprises several functional groups K3, preferably 2 to20, most preferably 5 to 10. Preferably, D3 comprises a terminalfunctional group K3.

The functional group K₃ in the side chain D3 is preferably selected fromthe group consisting of biotin, nitrilotriacetic acid (NTA), amines,carboxy, fluorescence markers, antibodies, peptide and a single strandedDNA fragment.

The term amines and carboxy of the functional group K₃ have the samemeaning as for the functional group K₁ of the side chain D1, but thechain R_(D3) which connects the functional group to the linker group Fis different from R_(D1).

Said chain between the linker group F and the functional group R_(D3) issaid chain may be selected from the group consisting ofpolydimethylsiloxane, perfluoroethers, perfluoroalkyls, polyisobutene,polyethylene glycol, polydimethylacrylamide, polyvinylpyrrolidone,polyalkyloxazolines, dextran, carboxymethyl dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), polyalkylene residueshaving more than 20 carbon atoms, peptide chains, DNA fragments,poly-(sulfobetaine methacrylate), and poly-(sulfobetaineacrylamide,preferably polydimethylacrylamide, polyalkyloxazoline and polyethyleneglycol, and most preferably polyethylene glycol.

Typically said chain R_(D3) has a molecular weight of 500 Da to 30′000Da, preferably from 5000 Da to 15′000 Da, resulting in a long chain sidechain D3.

Most preferably, R_(D3) is a polyethylene glycol oligomer having 5 to230, preferably 20 to 120 ethylene glycol units.

The term fluorescence marker stands for a fluorophore that provides avisual functionality to the polymer. Examples are xanthene, cyanine,naphthalene, coumarines, oxadiazole, anthracene, pyrene, oxazine,acridine, arylmethine, tetrapyrrole, benzofuranes, perylenes,benzanthrones, anthrapyrimidines or anthrapyridones. Side chains D3comprising a fluorescence marker as functional group K3 have alloutstanding fluorescent properties and are suitable for all differentsubstrate types such as metal oxides, glass, polymers, and noble metals.

If the functional group K₃ of side chain D3 is an antibody, it may beone of the antibodies known to the skilled persons.

If the functional group K₃ of side chain D3 is a peptide, it may be acustom synthesized peptide or a one of the known cell selective peptidesequences. Most preferred is a peptide sequence containing the RGDsegment.

If the functional group K₃ of side chain D3 is biotin of the formula 5

R_(D3-21) is a long chain as defined above, most preferably it ispolyethylene glycol.

If the functional group K₃ of the side chain D3 is nitrilotriacetic acid

R_(D3-22) is a long chain as defined above, preferably polyethyleneglycol.

Alternatively, the side chain D3 may be a peptide or a single strandedDNA fragment, which is linked to the polymer backbone by the linkergroup F.

The functional polymer according to the present invention must compriseat least one type of side chain E. The starting compound for the sidechain E has the following general formulaH—R_(E)—K₄ or H—K₄depending on whether there is an alkyl chain present between thefunctional group K4 and the functional group H. In said formulasH is the functional group, which is intended to react with the reactivegroup G of the polymer backbone resulting in the linker group F,R_(E) is the linear or branched C₁ to C₂₀, preferably C₁ to C₁₂ alkylgroup R_(E), which optionally comprises heteroatoms in the chain and maybe substituted or unsubstituted, andK₄ is a functional group, which will be defined further below.

The functional group K₄ of the side chain E is intended to irreversiblebind to a substrate. It is preferably selected from the group of alkoxysilanes, chloro silanes, catechols, phosphates, phosphonates, mimosinederivatives, anacheline, gallols, thiols, N-heterocyclic carbenes,perfluorophenyl azides, benozophenon, diaryldiazomethane,aryltrifluoromethyldiazomethane, and organoboron.

Preferably, the above mentioned functional group K3 is terminal.Although it is possible that the side chain E comprises more than onefunctional group, it comprises preferably only one functional group.

In the side chain E R_(E) is preferably selected from the groupconsisting of methylene, ethylene, propylene, butylene, pentylene,hexylene, heptylene, octylene, nonylene, decylene, undecylene,dodecylene, —(CH₂)—CH(COOH)—, —C(═O)—O—(CH₂)_(n)—; and—C(═O)—NH—(CH₂)_(n)—, wherein n=1 to 8. Most preferably R_(E) isselected from the group consisting of methylene, ethylene, propylene,butylene, —(CH₂)—CH(COOH)—, —C(═O)—O—(CH₂)_(n)—; and—C(═O)—NH—(CH₂)_(n)—, wherein n=1 to 8.

If the functional group in side chain E is an alkoxy silane of theformula

R_(E-30) is a linear or branched, saturated or unsaturated alkyl chainconnecting the linker group F and the alkoxy silane group. Preferably,R_(E-30) is selected from the group consisting of methylene, ethylene,propylene, and butylene. The silane group is preferably terminal. R₃₁and R₃₂ are selected from the group of methyl, ethyl, propyl orisopropyl, preferably methyl or ethyl and most preferably ethyl. Mostpreferably side chain E is propyldimethylethoxysilane orpropyldimethyldimethylmethoxysilane, which is preferably linked by anamine to the linker group F resulting for example in an amide.Alkoxysilanes form in particular good bondings to hydroxyl groups onsurfaces, metal oxides, glass, and polymers (in particular activatedpolymers).

If the functional group in side chain E is a chloro silane of theformula

R_(E-33) is a linear or branched, saturated or unsaturated alkyl chainconnecting the linker group F and the chloro silane group. PreferablyR_(E-33) is selected from methylene, ethylene, propylene, and butylene.The chloro silane group is preferably terminal. Most preferably sidechain E is propyldimethyldimethylchlorosilane or propyltrichlorosilanewhich are preferably linked by an amine to the linker group F resultingfor example in an amide. Chlorosilanes form in particular good bondingsto hydroxyl groups on surfaces, metal oxides, glass, polymers (inparticular activated polymers).

In the functional group in E is a catechol of the formula 12

wherein X₁ is H, F, Cl, Br, I, CF₃, acetyl, nitro, CH₃, —N(CH₃)₂,N(CH₃)₃ ⁺, SO₃ ⁻, or SO₂CF₃, R_(E-34) is preferably selected from thegroup of consisting of methylene, ethylene, propylene, butylene,pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecyleneand dodecylene, as well as —(CH₂)—CH(COOH—), —C(═O)—O—(CH₂)_(n=1-8)—;and —C(═O)—NH—(CH₂)_(n=1-8)—. Depending on the nature of the substratecatecholes have the ability to bind either covalent via condensationreaction or by coordination.

Each combination of R_(E-34) and X₁ is part of the present invention asshown in tables A1 and A2 and represents a specific type of side chainE:

TABLE A1 R_(E-34) X₁ —(CH₂) —(CH₂)₂ —(CH₂)₃ —(CH₂)₄ —(CH₂)₅ —(CH₂)₆—(CH₂)₇ —(CH₂)₈ H + + + + + + + + F + + + + + + + + Cl + + + + + + + +Br + + + + + + + + I + + + + + + + + CF₃, + + + + + + + +acetyl + + + + + + + + NO₂ + + + + + + + + CH₃ + + + + + + + +N(CH₃)₂ + + + + + + + + N(CH₃)₃ ⁺ + + + + + + + + SO₃ ⁻ + + + + + + + +SO₂CF₃ + + + + + + + +

TABLE A2 R_(E-34) X₁ —(CH₂)₉ —(CH₂)₁₀ —(CH₂)₁₁ —(CH₂)₁₂ —(CH₂)—CH(COOH—)H + + + + + F + + + + + Cl + + + + + Br + + + + + I + + + + +CF₃, + + + + + acetyl + + + + + NO₂ + + + + + CH₃ + + + + +N(CH₃)₂ + + + + + N(CH₃)₃ ⁺ + + + + + SO₃ ⁻ + + + + + SO₂CF₃ + + + + +R_(E-34) X₁ —(CH₂)CH(COOH)— —C(═O)—O—(CH2)_(n=1−8)——C(═O)—NH—(CH₂)_(n=1−8)— H + + + F + + + Cl + + + Br + + + I + + +CF₃, + + + acetyl + + + NO₂ + + + CH₃ + + + N(CH₃)₂ + + + N(CH₃)₃⁺ + + + SO₃ ⁻ + + + SO₂CF₃ + + +

Most preferably X₁ is hydrogen or nitro and R_(E-34) is ethylene, sincethis allows to use as starting compound nitrodopamine or dopamine.Catechols form in particular good bondings to metal oxides, especiallytransition metal oxides, and to metal surfaces (such as Ag, Au and Pt).

If the functional group in side chain E is a mimosine derivative of theformula 13 or 14

R_(E-35) and/or R_(E-35′) are preferably selected from the group of asubstituted or unsubstituted methylene, ethylene, propylene, butylene,pentylene, hexylene, heptylene and octylene, most preferably a carboxysubstituted ehtylene, which has the advantage that the amino acidminosine

can be used as starting compound and linked to the linker group G by theamine group. Mimosine derivatives form in particular strong covalent orcoordinative bonds to oxide surfaces, especially transition metaloxides, and to metal surfaces (such as Ag, Au and Pt).

If the functional group in E is anacheline of the formula

R_(E-36) is preferably a linear or branched, saturated or unsaturatedalkyl chain having 1 to 8 carbon atoms connecting the linker group F andthe anacheline group, the side chain E is preferably selected from thegroup of ethyl anacheline (R_(E-36)═(CH₂)₂), proply anacheline(R_(E-36)═(CH₂)₃), butyl anacheline (R_(E-36)═(CH₂)₄), pentyl anacheline(R_(E-36)═(CH₂)₅), hexyl anacheline (R_(E-36)═(CH₂)₆), heptyl anacheline(R_(E-36)═(CH₂)₇) and octyl anacheline (R_(E-36)═(CH₂)₈. Alternatively,R_(E-36) may be replaced by an amino group. Most preferably anachelineis coupled to the functional group G by its amino group. Anachelineforms in particular strong covalent or coordinative bonds to oxidesurfaces, especially transition metal oxides and to metal surfaces suchas (Ag, Au and Pt).

The term gallol stands for

wherein X₂ is H, F, Cl, Br, I, CF₃, acetyl, nitro, CH₃, —N(CH₃)₂,N(CH₃)₃ ⁺, SO₃ ⁻, or SO₂CF₃ and R_(E-37) is selected from the group ofmethylene, ethylene, propylene, butylene, pentylene, hexylene,heptylene, octylene nonylene, decylene, undecylene and dodecylene, aswell as —(CH₂)—CH(COOH—), —C(═O)—O—(CH₂)_(n=1-8)—; and—C(═O)—NH—(CH₂)_(n=1-8)—. Each combination of R_(E-37) and X₂ is part ofthe present invention as shown in tables B1 and B2 and represents aspecific type of side chain E:

TABLE B1 R_(E-37) X₂ —(CH) —(CH)₂ —(CH)₃ —(CH)₄ —(CH)₅ —(CH)₆ —(CH)₇—(CH)₈ H + + + + + + + + F + + + + + + + + Cl + + + + + + + +Br + + + + + + + + I + + + + + + + + CF₃, + + + + + + + +acetyl + + + + + + + + NO₂ + + + + + + + + CH₃ + + + + + + + +N(CH₃)₂ + + + + + + + + N(CH₃)₃ ⁺ + + + + + + + + SO₃ ⁻ + + + + + + + +SO₂CF₃ + + + + + + + +

TABLE B2 R_(E-37) X₂ —(CH₂)₉ —(CH₂)₁₀ —(CH₂)₁₁ —(CH₂)₁₂ —(CH₂)—CH(COOH—)H + + + + + F + + + + + Cl + + + + + Br + + + + + I + + + + +CF₃, + + + + + acetyl + + + + + NO₂ + + + + + CH₃ + + + + +N(CH₃)₂ + + + + + N(CH₃)₃ ⁺ + + + + + SO₃ ⁻ + + + + + SO₂CF₃ + + + + +R_(E-37) X₂ —C(═O)—O—(CH₂)_(n=1−8)— —C(═O)—NH—(CH₂)_(n=1−8)— H + + F + +Cl + + Br + + I + + CF₃, + + acetyl + + NO₂ + + CH₃ + + N(CH₃)₂ + +N(CH₃)₃ ⁺ + + SO₃ ⁻ + + SO₂CF₃ + +

Most preferably X₂ is hydrogen and R_(E-37) is —(CH₂)—CH(COOH—),—C(═O)—O—(CH₂)_(n=1-8)—; and —C(═O)—NH—(CH₂)_(n=1-8)—. Gallols form inparticular strong covalent or coordinative bonds to oxide surfaces.

The term thiols stands for R_(E-38)—SH. If the functional group K4 is athiol, R_(E-38) is preferably selected from the group of consisting ofmethylene, ethylene, propylene, butylene, pentylene, hexylene,heptylene, octylene, nonylene, decylene, undecylene, dodecylene,—(CH₂)—CH(COOH—), —C(═O)—O—(CH₂)_(n=1-8)—; and —C(═O)—NH—(CH₂)_(n=1-8)—.Most preferred are ethylene, hexylene and undecylene. Thiols form inparticular strong covalent bonds to nobel metals such as Ag, Au and Pt.

If the functional group in E is an N-heterocyclic carbene of the formula

wherein R_(E-38) is a linear or branched, saturated or unsaturated,substituted or non-substituted alkyl chain having 1 to 8 carbon atomsconnecting the linker group F and the N-heterocyclic carbene. R_(E-38)is preferably methylene, ethylene, —(CH₂)CH(COOH)—; —O—(CH₂)_(x=1-8);—C(═O)—O—(CH₂)_(n=1-8)—; —C(═O)—O—(CH₂)_(n=1-8) and—C(═O)—NH—(CH₂)_(n=1-8)—. N-heterocyclic carbenes form in particularstrong covalent bondings to noble metal surfaces (such as Au).

The term perfluorophenylazide stands for

wherein R_(E-39) is preferably a linear or branched, saturated orunsaturated alkyl chain having 1 to 8 carbon atoms. If the functionalgroup of side chain E is a perfluorophenylazide it is preferablyselected from the group of ethyl perfluoroazid, propyl perfluoroazid,butyl perfluoroazid, pentyl perfluoroazid, hexyl perfluoroazid, heptylperfluoroazid and octyl perfluoroazid or R_(E-39) is —(CH₂)CH(COOH)—;—O—(CH₂)_(n=1-8)—; —C(═O)—O—(CH₂)_(n=1-8)—; —C(═O)—NH—(CH₂)_(n=1-8)—.Azides upon activation with light or temperature form via anintermediate nitrene in particular good covalent insertions into bondsof polymers and coordination bondings to metals.

If the functional group in side chain E is benzophenone of the formula19

R_(E-40) is a linear or branched, saturated or unsaturated, substitutedor unsubstituted alkyl chain having 1 to 8 carbon atoms, preferably,methylene, ethylene, —(CH₂)CH(COOH)—; —O—(CH₂)_(n=1-8)—;—C(═O)—O—(CH₂)_(n=1-8)—; and —C(═O)—NH—(CH₂)_(n=1-8)—. The presence ofbenzophenone as functional group allows a covalent insertion into bondsof polymers after activation (via diradical). Therefore, said functionalgroup is especially preferred for polymer substrates.

If the functional group in side chain E is diaryldiazomethane of theformula 20

R_(E-41) is preferably a linear or branched, saturated or unsaturatedalkyl chain having 1 to 8 carbon atoms and most preferably, methylene,ethylene, —(CH₂)CH(COOH)—; —O—(CH₂)_(n=1-8)—; —C(═O)—O—(CH₂)_(n=1-8)—;and —C(═O)—NH—(CH₂)_(n=1-8)—. The presence of diaryldiazomethane asfunctional group allows a covalent insertion into bonds of polymersafter activation (via carbene). Therefore, said functional group isespecially preferred for polymer substrates.

If the functional group in side chain E isaryltrifluoromethyldiazomethane of the formula 21

R_(E-42) is a linear or branched, saturated or unsaturated alkyl chainhaving 1 to 8 carbon atoms and most preferably, methylene, ethylene,—(CH₂)CH(COOH)—; —O—(CH₂)_(n=1-8)—; —C(═O)—O—(CH₂)_(n=1-8)—; and—C(═O)—NH—(CH₂)_(n=1-8)—. The presence of diaryldiazomethane asfunctional group allows a covalent insertion into bonds of polymersafter activation (via carbene). Therefore, said functional group isespecially preferred for polymer substrates.

The term organoboron stands for

wherein X₃, X₄, and X₅ are independently from each other Cl or OH,R_(E-44) is methyl or ethyl, and R_(E-43) and R_(E-45) are a linear orbranched, saturated or unsaturated alkyl chains having 1 to 8 carbonatoms. Organoboron forms in particular strong covalent bondings topolymers and oxide surfaces.

The term phosphates stands for a monophosphate R_(E46)O—PO₃ ²⁻, whereinR_(E46) is preferably a linear unsubstituted C₁ to C₁₂ alkyl group. Ifthe functional group in E is a phosphate, E is preferably selected fromthe group of ethylene phosphate, propylene phosphate, butylenephosphate, pentylene phosphate, hexylene phosphate, heptylene phosphate,octylene phosphate, nonylene phosphate, decylene phosphate, undecylenephosphate and dodecylene phosphate, preferably hexylene phosphate anddodecylene phosphate. Phosphates form in particular good long rangeelectrostatic bondings to positive charged metal oxides and formcoordinative bonds to negative charged metal oxides. Within the contextof the present invention phosphates are considered to irreversible bindto a substrate.

The term phosphonates stands for phosphonates of the formulaR_(E-47)—CH₂—PO₃ ²⁻, wherein R_(E-47) is preferably a linear C₁ to C₈alkyl. If the functional group in E is a phosphonate, E is preferablyselected from the group of ethylene phosphonate, propylene phosphonate,butylene phosphonate, pentylene phosphonate, hexylene phosphonate,heptylene phosphonate octylene phosphonate, nonylene phosphonate,decylene phosphonate, undecylene phosphonate and dodecylene phosphonate,preferably hexylene phosphonate and dodecylene phosphonate. Phosphonatesform in particular good long range electrostatic bondings to positivecharged metal oxides and form coordinative bonds to negative chargedmetal oxides. Within the context of the present invention phosphonatesare considered to irreversible bind to a substrate.

In a preferred embodiment the functional polymer according to thepresent invention comprises 2 to 8 different types of side chains D and1 to 5 different types of side chains E. The 2 to 8 different types ofside chains may be different types of side chains D1, different types ofside chains D2, different types of side chains D3, a combination of sidechains D1 and D2, a combination of side chains D1 and D3, a combinationof side chains D2 and D3 as well as a combination of side chains D1, D2and D3. Most preferably the functional polymer comprises 2 to 5different types side chains D and 1 or 2 different types side chains E.

In a preferred embodiment of the present invention the functionalpolymer according comprises at least 1 type side chain D1 and at least 1type of side chain E, and preferably additionally at least 1 type ofside chain D2 and/or at least 1 type of side chain D3.

Preferably, the functional polymer comprises

-   (i) 1 or 2 different types of side chains D1 comprising functional    group K1 selected from the group consisting of amines, carboxy, poly    (propylene sulfid) and thioether, preferably amines or carboxy, most    preferably amines and,-   (ii) preferably 1 or 2, preferably 1, different types of side chains    D2 selected from the group of polyethylene glycol,    polydimethylacrylamide and polyalkyloxaoline, and-   (iii) 1 to 3 different, preferably 2 or 3, most preferably 3,    different types side chains E comprising a functional group K4 from    the group consisting of alkoxy silanes, chloro silanes, catechols,    phosphates, phosphonates or thiols, preferably of alkoxy silanes,    phosphates and catechols,-   (iv) and optionally 1 or 2, preferably 1, different type of side    chains D3 comprising a functional group K3 selected from the group    consisting of biotin and NTA.

Preferably, the functional polymer comprises

-   (i) a hexyl-amine as side chain D1,-   (ii) amine PEG (preferably 2 kDa) as side chain D2,-   (iii) amino propyldimethyl ethoxy silane and nitrodopanine as side    chains E (two types of side chains),-   (iv) and optionally amine PEG (preferably 3.5 kDa) biotin or amine    PEG (preferably 3.4 kDa) NTA as side chain D3.

A preferred polymer of the present invention is a polymer of thefollowing formula,

wherein the five different types of side chains may be regularly orrandomly distributed (in formula 24 n is 5 to 230, preferably 20 to120).

Preferably, the polymer according to the present invention is obtainedby a fast and versatile post-modification of the polymer backbone.Post-modifications of polymers are known in the art such as in Klok etal, Systhesis of functional polymers by post-polymerizationmodification, Angew. Chem. In. Ed. 2009, 48, 48 to 58.

Before carrying out the modification reaction the polymer backbonecomprises preferably reactive groups selected from the group of esters,activated esters, NHS esters, epoxides, anhydrides, azides, alkines,acyltrifluoroborates. Most preferably the reactive groups are activatedesters, obtained by using a radical polymerisation method. This can be afree radical polymerisation or a controlled radical polymerisation.

The preparation of a polymer according to the present inventioncomprising 5 different types of side chains can follow the followingprocedure:

-   1) Preparation of the polymer backbone comprising the reactive    groups G, preferably by using a radical polymerization protocol,-   2) reacting a first side chain D3 comprising a reactive group H with    the polymer backbone resulting in a linker group F,-   3) reacting a second side chain D2 comprising a reactive group H    with the polymer backbone resulting in a linker group F,-   4) reacting a third side chain D1 comprising a reactive group H with    the polymer backbone resulting in a linker group F,-   5) reacting a forth side chain E comprising a reactive group H with    the polymer backbone resulting in a linker group F,-   6) reacting a fifth side chain E comprising a reactive group H with    the polymer backbone resulting in a linker group F.

If necessary, the functional groups K1, K3 or K4 have to be protected.The addition of the different types of side chains can occursequentially or in parallel, preferably sequentially. Preferably, thebulky side chains D2 and/or D3 are added to the polymer backbone first,and subsequently the shorter chains D1 and/or E are added.

In a preferred embodiment of the present invention the polymer backbonebefore carrying out the modification reactions is a pentafluorophenolester or a pentachlorophenol ester, preferably a poly(pentafluorophenolacrylate), poly(pentafluorophenol methacrylate), poly(pentachlorophenolacrylate), poly(pentachlorophenol methacrylate), and most preferably apoly(pentafluorophenol acrylate).

The functional polymer according to the present invention can preferablybe deposited on the substrate by dip coating, spin coating, spraying,printing, coating or solvent casting. In all cases, the solutioncontaining the functional polymer gets preferably in contact with thesubstrate to be modified so that the moieties can graft chemically ontothe surface. The obtained coating is depending of the architecture ofthe molecules used and can vary from a monomolecular thick layer havinga thickness of 0.1 to 10 nanometers, preferably 1 to 3 nanometers, to amultilayered system with a thickness of 10 nanometer to 10 micrometers,preferably 10 to 50 nanometers.

The functional polymers according to the present invention arepreferably for coating systems on different substrate, in particular onmetal oxides, such as silicon dioxide or transition metal oxides,preferably TiO₂, Nb₂O₅, Ta₂O₅, Fe₂O₃, Fe₃O₄, on noble metal surfaces,such as gold, silver and platinum, and polymers such as polyethylene.The functional polymer according to the present invention can be used asmulti-functional coatings or it can have a very specific coatingfunction, that is it can be for example an anti-fouling coating. Asubstrate in the context of the present invention may be a surface, inparticular a two-dimensional surface, as well as nanoparticles ormicroparticles, which are to be partly or fully covered with thefunctional polymer according to the present invention.

For a metal oxide substrate, in particular a silicon dioxide or titaniumdioxide, the polymer according to the present invention comprisespreferably

at least one type of side chain is a side chain D1, wherein thefunctional group is preferably selected from amines, carboxy, and/or

at least one type of side chain is a side chain D2,

at least one type of side chain is a side chain E, wherein thefunctional group is preferably selected from the group consisting ofcatechols, mimosine derivatives, anacheline, gallols and organoboron.

In addition, it can optionally comprise at least one type of side chainD3, wherein the functional group is preferably selected from the groupconsisting of amines, carboxy and biotin.

For a substrate with a noble metal surface, in particular silver or goldsurface, the functional polymer according to the present inventioncomprises preferably

at least one type of side chain is a side chain D1, wherein thefunctional group is selected from the group consisting of amine,thioether and poly(propylene sulfide),

at least one type of side chain is a side chain D2 having no functionalgroup, and

at least one type of side chain is a side chain E, wherein thefunctional group is preferably selected from the group consisting ofcatechol, thiols, and N-heterocyclic carbenes.

In addition, it can optionally comprise at least one type of side chainD3, wherein the functional group is preferably consisting of amines,carboxy and biotin.

For a polymer substrate, in particular for polyethylene, the functionalpolymer according to the present invention comprises preferably

at least one type of side chain is a side chain D1, wherein thefunctional group is selected from the group consisting of amine andcarboxy,

at least one type of side chain is a side chain D2 having no functionalgroup, and

at least one type of side chain is a side chain E, wherein thefunctional group is preferably selected from the group consisting ofalkoxysilane, chlorosilane, perfluoroazide, benzophenone,diaryldiazomethane, aryltrifluoromethyldiaomethan, and organoboron.

In addition, it can optionally comprise at least one type of side chainD3 wherein the functional group is preferably consisting of amines,carboxy and biotin.

EXPERIMENTAL PART Example 1: Synthesis of Polypentafluorophenyl Acrylate(PPFPAc)

The monomer pentafluorophenyl acrylate (PFPAc) is a well-knowncommercially available product and was prepared according to thepreviously reported protocol (Eberhardt, M., & Theato, P. (2005). RAFTpolymerization of PFPAc: preparation of reactive linear diblockcopolymers. Macromolecular Rapid Communications, 26(18), 1488-1493).Briefly, pentafluorophenol (87.21 g, 0.47 mol) was dissolved in 150 mLof CH₂Cl₂ at 0° C. and 2,6-dimethylpyridine (60.55 mL, 0.52 mol) wasadded slowly through a dropping funnel, which was afterwards rinsed withanother 150 mL of CH₂Cl₂ also added to the reaction mixture. Acryloylchloride (42.14 mL, 0.52 mol) was then added dropwise to the reactor,still under cooling, and left to react for 18 h under N2 atmospherewhile warming up to room temperature. The resulting 2,6-dimethylpyridinehydrochloride salt was removed by filtration and the subsequent solutionwas washed three times with 100 mL of water, dried with MgSO₄ and thesolvent evaporated under reduced pressure. The product was purifiedtwice by vacuum distillation to obtain the pure monomer as a colorlessliquid (97.09 g, 78%).

¹H NMR (CDCl₃, δ/ppm): 3.1 ppm (1H, a) and 2.1 ppm (2H, br s).

The monomer PFPAc (14.31 g, 60.13 mmol), the initiator AIBN (23.83 mg,0.15 mmol) and the chain transfer agent2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (158.45 mg, 0.43mmol) were dissolved in 15 mL of toluene inside a Schlenk-tube. Thesolution was degassed via three freeze-pump-thaw cycles and left toreact under nitrogen atmosphere at 80° C. in an oil bath for 18 h. Thereaction mixture was left to cool down to room temperature and theresulting polymer (PPFPAc) was isolated by precipitation in methanol anddried under vacuum for 48 h (Yield: 12.90 g, 90%)

GPC (THF): M_(n)=12800 g mol⁻¹, M_(w)=19300 g mol⁻¹, PDI=1.51.

FTIR (KBr, cm⁻¹); 2950 (C—H stretch), 1800 (C═O stretch), 1525 (aromaticC—C), 950-1250 (C—F stretch).

¹H NMR (CDCl₃, δ/ppm): —CH— 3.1 (1H, br, s), —CH₂— 2.15 (2H, br, s)

Anal. Calcd. for (C₈H₃F₅)_(n): C, 45.37, H, 1.26, O, 13.45, F, 39.92.Found: C, 45.40, H, 1.27, O, 13.44, F, 39.89.

Example 2: First Stage Postmodification of PPFPAc: PEGylation forNon-Fouling Functionality

In order to obtain non-fouling properties, the backbone from Example 1was modified with the polymer methoxy-poly(ethylene glycol)-aminehydrochloride (PEG-NH2 HCl, 2000 g mol⁻¹). Briefly, 79.4 mg (0.333 mmolper monomer) of PPFPAc was dissolved in dimethylformamide (DMF) understirring at a temperature of 50° C. Separately, 100 mg of PEG-NH2 HClwas dissolved in DMF (0.050 mmol) together with a 2 to 3-fold excess oftriethylamine. The PEG solution was then added to the initial reactivemixture drop-wise and left to react overnight to obtain a PEG graftingdensity of 0.15. The resulting solution of poly(acrylic acid)-g-(PFPAc,PEG) (238.11:2000 Mr; 0.85:0.15 d), was used for furtherpostmodification as described in the following section.

¹H NMR (CDCl₃, δ/ppm): —CH₂—O—CH₂— 3.5-3.8 (180H, m), —O—CH₃ 3.4 (3H,s), —CH₂—NH—C(═O)— 3.1 (2H, m).

Example 3: Second Stage Postmodification of PPFPAc: Binding Side Groups

All polymer combinations presented below started from the pegylatedversion of poly(acrylic acid)-g-(PFPAc, PEG) (238.11:2000 Mr; 0.85:0.15d) described in Example 2.

Polymer A

poly(acrylic acid)-g-(PEG, 1,6-hexanediamine) (2000:116.2 Mr; 0.15:0.85d): 107.43 mg (0.425 mmol) of N-Boc-1,6-hexanediamine hydrochloride wasdissolved in 1 mL of DMF with an excess of triethylamine (177.71 μL,1.275 mmol). The mixture was added drop-wise to the poly(acrylicacid)-g-(PFPAc, PEG) (238.11:2000 Mr; 0.85:0.15 d) solution prepared asin example 2 and left to react overnight under stirring at 50° C. DMFwas evaporated under reduced pressure, the mixture re-dissolved indichloromethane (DCM, 2 mL, 4 equivalents) and trifluoroacetic acid (0.5mL, 1 equivalent) and left to react under stirring overnight. Theresulting mixture was again evaporated under reduced pressure andre-dissolved in ultrapure water (5 mL). This solution was purified bydialysis against water for two days using a membrane with a MWCO of3,500 Da and subsequently freeze dried to obtain the polymer as a whitepowder (yield: 133.77 mg, 77.24%).

Polymer B

poly(acrylic acid)-g-(PEG, 1,6-hexanediamine,3-aminopropyldimethylethoxysilane) (2000:116.2:161.3 Mr;0.15:0.425:0.425 d): 35.81 mg (0.142 mmol) of N-Boc-1,6-hexanediaminehydrochloride was dissolved in 1 mL of DMF with an excess oftriethylamine (59.2 uL, 0.425 mmol). The mixture was added drop-wise tothe Poly(acrylic acid)-g-(PFPAc, PEG) (238.11:2000 Mr; 0.85:0.15 d)solution from example 2 and left to react overnight under stirring at50° C. A new solution containing 45.71 mg (0.283 mmol) of3-aminopropyldimethylethoxysilane and triethylamine (118.47 μL, 0.85mmol) in 1 mL of DMF was added drop-wise to the previous solution stillat 50° C. and under stirring overnight. Deprotection of the amine andpurification followed as described for polymer A.

Polymer C

poly(acrylic acid)-g-(PEG, 1,6-hexanediamine, nitrodopamine)(2000:116.2:198.2 Mr; 0.15:0.425:0.425 d): postmodification withN-Boc-1,6-hexanediamine hydrochloride was as described in polymer B. Anexcess of nitrodopamine was dissolved separately (83.94 mg, 0.283 mmol)in 1 mL of DMF with 118.47 μL of triethylamine (0.85 mmol). The lattersolution was added slowly to the hexanediamine solution and leftstirring overnight at the same temperature. Deprotection of the amineand purification followed as described for polymer A.

Polymer D

poly(acrylic acid)-g-(PEG, 1,6-hexanediamine,12-aminododecylphosphonate) (2000:116.2:265.3 Mr; 0.15:0.425:0.425 d):postmodification with N-Boc-1,6-hexanediamine hydrochloride was asdescribed in polymer B. To this a solution containing12-aminododecylphosphonate-bistrimethylsilylester and 118.47 μL oftriethylamine (0.85 mmol) in 1 mL of DMF (85.33 mg, 0.283 mmol) wasadded drop-wise. The resulting polymer solution was left reactingovernight at 50° C. while stirring, followed by the deprotection of theamine and phosphonate and purification as described for polymer A.

Polymer E

poly(acrylic acid)-g-(PEG, 1,6-hexanediamine, ethanolamine)(2000:116.2:61.1 Mr; 0.15:0.425:0.425 d): postmodification withN-Boc-1,6-hexanediamine hydrochloride was as described in polymer B,after which an excess containing solution of ethanolamine (17.31 mg,0.283 mmol) and triethylamine (118.47 μL, 0.85 mmol) in 1 mL of DMF wasslowly added. The resulting polymer solution was left reacting overnightat 50° C. while stirring, followed by the deprotection of the amine andpurification as described for polymer A.

Polymer F

poly(acrylic acid)-g-(PEG, 1,6-hexanediamine,3-aminopropyl-dimethylethoxysilane, nitrodopamine)(2000:116.2:161.3:198.2 Mr; 0.15:0.425:0.2125:0.2125 d):postmodification with N-Boc-1,6-hexanediamine hydrochloride was asdescribed in polymer B. Afterwards a solution of3-aminopropyldimethylethoxysilane (11.43 mg, 0.071 mmol) andtriethylamine (29.62 μL, 0.21 mmol) in 1 mL of DMF was added dropwiseand left stirring overnight at 50° C. A last solution of excessnitrodopamine (41.97 mg, 0.142 mmol) in DMF (1 mL) and triethylamine(59.24 μL, 0.43 mmol) was added dropwise. The resulting polymer solutionwas left reacting overnight at 50° C. while stirring, followed by thedeprotection of the amine and purification as described for polymer A.

Polymer G

poly(acrylic acid)-g-(PEG, 3-aminopropyl-dimethylethoxysilane,nitrodopamine) (2000:161.3:198.2 Mr; 0.15:0.425:0.425 d): 22.85 mg(0.142 mmol) of 3-aminopropyldimethylethoxysilane previously dissolvedin 1 mL of DMF and containing excess triethylamine (59.24 μL, 0.425mmol) was added to a solution of poly(acrylic acid)-g-(PFPAc, PEG)(238.11:2000 Mr; 0.85:0.15 d). After reacting overnight at 50° C. understirring a new solution of excess nitrodopamine (83.94 mg, 0.283 mmol)and triethylamine (59.24 μL, 0.43 mmol) in 1 mL of DMF was addeddropwise. The resulting polymer solution was left to react overnight at50° C. while stirring, followed by the deprotection of the amine andpurification as described for polymer A.

Polymer

H poly(acrylic acid)-g-(PEG, 3-aminopropyl-dimethylethoxysilane)(2000:161.3 Mr; 0.15:0.85 d): excess of3-aminopropyldimethylethoxysilane (0.425 mmol, 68.56) and triethylamine(1.275 mmol, 177.71 μL) was added to a 2 mL solution of poly(acrylicacid)-g-(PFPAc, PEG) (238.11:2000 Mr; 0.85:0.15 d) as prepared inExample 2. The reaction was left overnight stirring at 50° C.Purification was performed as described for polymer A.

Polymer I

poly(acrylic acid)-g-(PEG, nitrodopamine) (2000:198.2 Mr; 0.15:0.85 d):167.88 mg of excess nitrodopamine (0.57 mmol) and 236.95 μL oftriethylamine were dissolved in 2 mL of DMF and added to a solution ofpoly(acrylic acid)-g-(PFPAc, PEG) (238.11:2000 Mr; 0.85:0.15 d) and leftto react at 50° C. under stirring overnight. Purification was performedas described for polymer A.

Polymer J

poly(acrylic acid)-g-(PEG, 12-aminododecylphosphonate) (2000:265.3 Mr;0.15:0.85 d): 170.66 mg of excess12-aminododecylphosphonate-bistrimethylsilylester (0.57 mmol) and 236.95μL of triethylamine (1.7 mmol) were dissolved in 2 mL of DMF and addedto a solution of poly(acrylic acid)-g-(PFPAc, PEG) (238.11:2000 Mr;0.85:0.15 d) and left to react at 50° C. under stirring overnight.Purification was performed as described for polymer A.

Polymer K

poly(acrylic acid)-g-(PEG, ethanolamine) (2000:61.1 Mr; 0.15:0.85 d):34.61 mg of excess ethanolamine (0.57 mmol) and 118.47 μL oftriethylamine (0.85 mmol) were dissolved in 2 mL of DMF and added to asolution of poly(acrylic acid)-g-(PFPAc, PEG) (238.11:2000 Mr; 0.85:0.15d) and left to react at 50° C. under stirring overnight. Purificationwas performed as described for polymer A.

Example 4: Polymer A, C, E or I on TiO₂

20 nm TiO₂ sputter coated Si-wafers were sonicated 2×15 min in toluene,2×15 min in 2-propanol, dried under a stream of N₂ and O₂-plasma cleanedfor 2 min.

Samples were then immersed overnight (in dark at room temperature) in a0.1 mg/mL solution (1 mM HEPES buffer, pH=7.4) of polymers A, C, E or I.Upon adsorption, the samples were rinsed once with the above-mentionedbuffer, once with water and dried under a stream of N₂. Thicknesses ofthe samples were measured before and after incubation by ellipsometry.

Subsequently, in order to test adlayer stability, the samples wereimmersed overnight (at RT) in sodium chloride solutions at pH 7.4 withdifferent ionic strength. Two ionic concentrations were used: a lowconcentrated one of 0.16M and 10 mM HEPES buffer (HEPES II) and a 2Msolution. The samples were then removed from the salt solution, rinsedonce with 1 mM HEPES buffer, once with water and dried under a stream ofN₂. The adlayer thickness was then measured by ellipsometry.

Finally, the samples were re-immersed in HEPES II for 15 min and exposedto human serum (Precinorm Roche) for 30 min. During incubation, thesamples were stored under ambient conditions without agitation. Afterexposure, the samples were rinsed twice with HEPES II buffer followed byultrapure water and dried under a stream of N₂. The protein uptake wasdetermined again by ellipsometry.

FIG. 1 shows Adsorption and stability (exposure to solution) and proteinresistance results on titanium oxide surfaces of four post-modifiedpolymers: polymer A (Amine), polymer E (Amine-Ethanolamine), polymer C(Amine-Nitrodopamine) and polymer I (Nitrodopamine). The graph on theleft shows the results of the polymeric coatings when exposed to a lowionic strength medium (HEPES II 0.16M) during the stability test step,while on the right they were exposed to a high ionic strength medium(NaCl 2M).

Results show the predictable formation of a polymeric film thicknessdepending on the type of chemistry used for binding. In the case wheresolely electrostatic binding was involved (amine and amine-ethanolamine)the initial adlayer thickness, around 1.75 nm, was not maintained evenafter overnight exposure in low ionic strength medium (HEPES II—H2).This is an expected result, as the salts are known to screen therepulsion between charged segments of the polymer and the electrostaticinteraction between the film and the substrate. Loosing theelectrostatic attraction to the surface, the polymers start to coil andeventually desorb from the surface, leading to a decrease in thickness.However the value obtained after H2 immersion (around 1 nm) seemssufficient to maintain the protein resistance of the functionalizedsurface, while after an exposure to the 2M salt solution, the samplesare not protein resistant anymore.

The maximum thickness was obtained when both the amine and thenitrodopamine are present and it prevailed after exposure to both lowand high ionic strength media. Similar stability was also observed inthe case where only nitrodopamine was used as a binding group to thetitania but with lower thickness values. Nevertheless, total proteinresistance was obtained only in the former case independently of theionic strength the surfaces were exposed to. This fact suggests that thepresence of long range interactions (electrostatic forces) are neededboth to act as a driving force for the polymer to reach the substrateand assemble itself but also for it to adopt the optimal conformationfor a nonfouling surface with PEG exposed to the solution-surfaceinterface. Covalent binding is equally necessary specially to enhancethe stability of the adlayer under harsh conditions such as high ionicstrength.

Example 5: Polymer A, E, B and H on SiO₂

One side polished Si-wafers were cleaned, adlayer of four polymers(Polymer A, E, B and H) were prepared, stability test and proteinresistance were performed all following the protocol of Example 4. Theadlayer thickness after the different steps was determined byellipsometry.

FIG. 2 shows Adsorption and stability (exposure to solution) and proteinresistance results on silicon oxide surfaces of four post-modifiedpolymers: polymer A (Amine), polymer E (Amine-Ethanolamine), polymer B(Amine-Silane) and polymer H (Silane). The graph on the left shows theresults of the polymeric coatings when exposed to a low ionic strengthmedium (HEPES II 0.16M) during the stability test step, while on theright they were exposed to a high ionic strength medium (NaCl 2M).

The trend observed in the previous example for the first two testedpolymers A and F (amine and amine-ethanolamine) is the same as for TiO₂as both substrates have negatively charged interfaces at neutral pH.When silane is added to the reactive backbone along with amine (polymerB) there is a slight reduction of the thickness of the adlayer after thestability test but protein resistance is maintained whether thefunctionalized surface has been exposed to low or high ionic strengthmedium. This shows that the polymer architecture is ideal and stable,much as in the previous case of polymer C (amine-nitrodopamine—seeFIG. 1) on TiO₂. When just having silane as a binding group, althoughideal for a silicon oxide surface, the initial adlayer adopts arelatively higher thickness than all the other polymers, indicating thata different conformation of the polymer is obtained that is not proteinresistant in any of the cases. It is polymer B with groups that bindboth electrostatic and covalently to the surface that outperforms allthe other combinations for the reasons stated in the previous example.

Example 6: Polymer A, E, D and J on TiO₂

20 nm TiO₂ sputter coated Si-wafers were cleaned, adlayer of fourpolymers (Polymer A, E, D and J) were prepared, stability test andprotein resistance were performed all following the protocol of Example4. The adlayer thickness was determined by ellipsometry after thedifferent steps.

FIG. 3 shows Adsorption and stability (exposure to solution) and proteinresistance results on titanium oxide surfaces of four post-modifiedpolymers: polymer A (Amine), polymer E (Amine-Ethanolamine), polymer D(Amine-Phosphonate) and polymer J (Phosphonate). The graph on the leftshows the results of the polymeric coatings when exposed to a low ionicstrength medium (HEPES II 0.16M) during the stability test step, whileon the right they were exposed to a high ionic strength medium (NaCl2M).

Similarly to example 4, in the case where the surfaces were exposed toH2 for stability, there is an overall loss in initial thickness but allcombinations containing the electrostatic contribution revealed to beprotein resistant. This again shows that the latter has an importantrole when it comes for the polymer to adopt the optimal conformation tothis end (nonfouling). When exposing the surfaces to a higher ionicstrength medium then all surfaces loose their ability to preventfouling. The same did not happen with the other titania-selective groupnitrodopamine, which indicates this latter forms a more stable bond withthe substrate than the phosphonate group.

Example 7: Polymer A, E, F1, F2* and G on TiO₂ and SiO₂

Both substrates, one side polished Si-wafers and 20 nm TiO₂ sputtercoated Si-wafers were cleaned as described previously and adlayers offive polymers (Polymer A, E, F1, F2* and G) were prepared. Similarly asin the previous examples, stability test and protein resistance wereperformed following the protocol of Example 4 where the adlayerthickness was determined by ellipsometry after the different steps. *Polymer F (F1, F2) was synthesized in two different ways where thecovalent groups (silane and nitrodopamine) were added in opposite order.

FIG. 4 shows adsorption and stability (exposure to solution) and proteinresistance results on silicon oxide surfaces of five post-modifiedpolymers: polymer A (Amine), polymer E (Amine-Ethanolamine), polymer F1(Amine-Nitrodopamine-Silane), Polymer F2 (Amine-Silane-Nitrodopamine)and polymer G (Silane-Nitrodopamine). The graph on the left shows theresults of the polymeric coatings when exposed to a low ionic strengthmedium (HEPES II 0.16M) during the stability test step, while on theright they were exposed to a high ionic strength medium (NaCl 2M).

FIG. 5 shows adsorption and stability (exposure to solution) and proteinresistance results on titanium oxide surfaces of five post-modifiedpolymers: polymer A (Amine), polymer E (Amine-Ethanolamine), polymer F1(Amine-Nitrodopamine-Silane), Polymer F2 (Amine-Silane-Nitrodopamine)and polymer G (Silane-Nitrodopamine). The graph on the left shows theresults of the polymeric coatings when exposed to a low ionic strengthmedium (HEPES II 0.16M) during the stability test step, while on theright they were exposed to a high ionic strength medium (NaCl 2M).

For both substrates, and as already explained in examples 4, 5 and 6,the surfaces that possess an electrostatic driven polymeric conformationshowed no protein uptake after being exposed to H2. As polymer Gcontains no amines attached to the backbone, even so it adsorbs, thepolymer is not organized in a way that the PEG side chains adopt abrush-like structure and hence the surface is not protein resistant.

After exposing the surfaces to a 2M salt solution the polymers withoutgroups that can attach to SiO₂ or TiO₂ covalently, or have noelectrostatic contribution (Polymers A, E and G), they do not retaintheir resistance to human serum. The foreseen exceptions are the twovariations of polymer F. When adding first the silane and thennitrodopamine, the resulting polymer maintains its resistance on bothsubstrates even after an exposure to a high ionic strength medium. Thesame does not happen when adding first the nitrodopamine and then thesilane. In this case its nonfouling ability is only maintained on TiO₂.This is an indication that the addition order of the chemicals whilepostmodifying PPFPAc does play a role, presumably due to the bulkinessof the dopamine group which, after attachment, might promote sterichindrance limiting the access of the silane group to the ester. Thismight be an explanation why on SiO₂ the resistance of polymer F1(amine-nitrodopamine-silane) polymer was not maintained: there was notenough silane groups to guarantee a stable covalent bond throughout thepolymeric backbone.

Example 8: Stability Against Acid

The influence of pH on stability/desorption of polyelectrolytes is awell known and common assay to be performed. In this example, andfollowing the protocol described in Example 4, two polymer combinationswere used to functionalize both SiO₂ and TiO₂ and before exposed tohuman serum, their stability was tested by immersing the surfaces in aglycine-HCl (10 mM-pH=2.4) buffer for 30 min at room temperature.Results are shown in FIG. 6.

FIG. 6 shows adsorption and stability (exposure to an acidic solutionglycine-HCl 10 mM-pH=2.4 overnight) and protein resistance results oftwo post-modified polymers: polymer A (Amine) and polymer F(Amine-Nitrodopamine-Silane). The graph on the left shows the results onsilicon oxide surfaces while the graph on the right shows the data ontitanium oxide surfaces.

The data presented in FIG. 6 reveals that both polymeric combinations onboth substrates suffer a reduction of their absolute thickness afterexposure to the acid solution. Nevertheless, the cases where an adlayerof at least 1 nm remains after the stability test, protein resistance ismaintained. The latter includes polymer F on both substrates and polymerA on TiO₂, confirming the importance of having a balance betweenelectrostatic and covalent binding to both stabilize and maintain thenonfouling ability of the coating in this particular assay.

Example 9: Stability Against Surfactants

The effect of surfactants on polymer adlayer stability was tested byexposing surfaces functionalized with polymer A (full electrostaticbinding to both SiO₂ and TiO₂) and polymer F (mix of electrostatic andcovalent bonds to the metal surfaces) to an anionic and cationicsurfactant, SDS and CTAB respectively, at 0.5% w/v for 30 min. Thesurfaces were modified according to the protocol described in Example 4and after the stability test was performed, their protein resistance wasassessed in a similar way as described previously.

FIG. 7 shows adsorption, stability (exposure to the cationic CTABsurfactant) and protein resistance results of polymer A and polymer F.The graph on the left shows the results on silicon oxide surfaces whilethe graph on the right shows the data on titanium oxide surfaces. As canbe observed in FIG. 7, polymer A's exposure to a cationic surfactant(CTAB) has a larger effect on the adlayer on SiO2 than on TiO2. In thefirst case the thickness obtained after the test was below 1 nm, whichtranslated into protein uptake, while in the case of titania thethickness before and after CTAB exposure did not differ much, allowingthe coating to maintain its protein resistance. One could state thatthere is a more relevant adsorption competition between surfactant andpolymer in the case of the negatively charged silicon oxide than ontitania, which is closer to its isoelectric point under theseconditions.

FIG. 8 shows Adsorption, stability (exposure to the anionic SDSsurfactant) and protein resistance results of polymer A and polymer F.The graph on the left shows the results on silicon oxide surfaces whilethe graph on the right shows the data on titanium oxide surfaces. In thecase of SDS (see FIG. 8), polymer A results show a considerable decreasein thickness on both substrates (again more pronounced in the SiO2case), which explains the protein uptake. In this case the cationicpolymer adlayer is now displaced from the substrate by the anionicsurfactant. Although the polymer layer is just bound electrostaticallyto both metal surfaces, it is clear that in the two cases the layer'sstructure is more stable on TiO2 than on SiO2. However when polymer F onSiO2 or TiO2 are exposed to the two surfactants (see both FIG. 7 andFIG. 8), the graphs clearly show that the stability of the polymericcoating is not compromised and it maintains its protein resistance. Thisis due to the covalent bonds formed (silane on SiO2, nitrodopamine onTiO2) which prevent significant polymer desorption from the surfaceduring surfactant exposure.

The invention claimed is:
 1. Functional polymer comprising at least twodifferent types of side chains, the polymer having the general formula(1),

wherein A is a monosubstituted alkylene or arylene group, B is an amide,an ester or an ether group and n is either 0 or 1, F is selected fromthe group of an ester, a secondary amine, an amide, an ether, a thioether, a thio ester, and may be the same or different for the differenttypes of side chains, D is a side chain which is intended to reversiblebind to a substrate or has a coating function, and D is selected fromthe group consisting of: a short chain side chain D1 having a linear orbranched, substituted or unsubstituted C₁ to C₁₂ alkyl group R_(D1)which optionally comprises heteroatoms and which carries at least onefunctional group K1; a side chain D2 having a long chain R_(D2) having amolecular weight of at least 500 Da and selected from the groupconsisting of polydimethylsiloxane, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-(hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide),whereby D2 has no functional end group or side group K1, K3 or K4; and aside chain D3 having a long chain R_(D3) having a molecular weight of atleast 500 Da and selected from the group consisting of apolydimethylsiloxane, perfluoroethers, perfluoroalkyls, polyisobutene,polyethylene glycol, polydimethylacrylamide, polyvinylpyrrolidone,polyalkyloxazolines, dextran, carboxymethyl dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-(hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide) wherebyD3 carries at least one functional end or side group K3, E is a sidechain which is intended to irreversibly bind to a substrate, the sidechain E having either a linear or branched, substituted or unsubstitutedC₁ to C₂₀ alkyl group R_(E) which optionally comprises heteroatoms andcarries at least one functional end group K4, or is the functional endgroup K4, the polymer comprises 2 to 8 different types of side chains Dand 1 to 5 different types of side chains E, the polymer comprising aplurality of each type of side chain, whereby a post-modificationprocedure is used to sequentially add the different types of side groupsto a backbone of a polymer intermediate comprising reactive groups inorder to randomly or regularly distribute the different types of sidechains in the polymer, the polymer comprises (i) at least 1 type of sidechain D1, and (ii) at least 1 type of side chain D2 and/or at least 1type of side chain D3, the functional group K1 in side chain D1 isselected from the group consisting of amines, carboxy, poly (propylenesulfide), and thioethers, the functional group K3 in side chain D3 isselected from the group consisting of amines, carboxy, fluorescencemarkers, antibodies, biotin, nitrilotriacetic acid (NTA), peptides, anda single stranded DNA fragment, and the functional group K4 in sidechain E is anacheline which is bound directly to the functional group F.2. Functional polymer according to claim 1, wherein side chain D2 isselected from the group of consisting of polydimethylacrylamide,polyalkyloxazoline and polyethylene glycol.
 3. Functional polymeraccording to claim 1, wherein at least one of R_(D1) in side chain D1and R_(E) in side chain E is selected from the group consisting ofmethylene, ethylene, propylene, butylene, pentylene, hexylene,heptylene, octylene, nonylene, decylene, undecylene dodecylene,—(CH₂)—CH(COOH)—, —C(═O)—O—(CH₂)_(n)—; and —C(═O)—NH—(CH₂)_(n)—, and n=1to
 8. 4. Functional polymer according to claim 1, wherein the polymerbackbone before carrying out a modification reaction is a polymer strandcomprising reactive groups G selected from the group consisting ofesters, activated esters, chloro, fluoro, acrylates, methacrylates, NHSesters, epoxides, anhydrides, azides, alkines, and acyltrifluoroborates.5. A method comprising coating the functional polymer according to claim1 in a monomolecular layer having a thickness of 0.1 to 10 nanometers,or coating the functional polymer according to claim 1 in a multilayeredsystem having a thickness of 10 nanometer to 10 micrometers.
 6. A methodcomprising applying a functional polymer according to claim 1 as coatingof a substrate selected from the group consisting of metal oxides, noblemetal surfaces, and polymers.
 7. A method comprising applying afunctional polymer according to claim 1 as anti-fouling coatings or asmulti-functional coatings.
 8. Functional polymer comprising at least twodifferent types of side chains, the polymer having the general formula(1),

wherein A is a monosubstituted alkylene or arylene group, B is an amide,an ester or an ether group and n is either 0 or 1, F is selected fromthe group of an ester, a secondary amine, an amide, an ether, a thioether, a thio ester, and may be the same or different for the differenttypes of side chains, D is a side chain which is intended to reversiblebind to a substrate or has a coating function, and D is selected fromthe group consisting of: a short chain side chain D1 having a linear orbranched, substituted or unsubstituted C₁ to C₁₂ alkyl group R_(D1)which optionally comprises heteroatoms and which carries at least onefunctional group K1; a side chain D2 having a long chain R_(D2) having amolecular weight of at least 500 Da and selected from the groupconsisting of polydimethylsiloxane, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-(hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide),whereby D2 has no functional end group or side group K1, K3 or K4; and aside chain D3 having a long chain R_(D3) having a molecular weight of atleast 500 Da and selected from the group consisting of apolydimethylsiloxane, perfluoroethers, perfluoroalkyls, polyisobutene,polyethylene glycol, polydimethylacrylamide, polyvinylpyrrolidone,polyalkyloxazoline, dextran, carboxymethyl dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-(hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide) wherebyD3 carries at least one functional end or side group K3, E is a sidechain which is intended to irreversibly bind to a substrate, the sidechain E having either a linear or branched, substituted or unsubstitutedC₁ to C₂₀ alkyl group R_(E) which optionally comprises heteroatoms andcarries at least one functional end group K4, or is the functional endgroup K4, the polymer comprises 2 to 8 different types of side chains Dand 2 to 5 different types of side chains E, the polymer comprising aplurality of each type of side chain, whereby a post-modificationprocedure is used to sequentially add the different types of side groupsto a backbone of a polymer intermediate comprising reactive groups inorder to randomly or regularly distribute the different types of sidechains in the polymer, the polymer comprises (i) at least 1 type of sidechain D1, and (ii) at least 1 type of side chain D2 and/or at least 1type of side chain D3, the functional group K1 in side chain D1 isselected from the group consisting of amines, carboxy, poly (propylenesulfide), and thioethers, the functional group K3 in side chain D3 isselected from the group consisting of amines, carboxy, fluorescencemarkers, antibodies, biotin, nitrilotriacetic acid (NTA), peptides, anda single stranded DNA fragment, the functional group K4 in side chain Eis selected from the group consisting of alkoxy silanes, chloro silanes,nitrocatechol phosphates, phosphonates, mimosine derivatives,anacheline, gallols, thiols, N-heterocyclic carbenes, perfluorophenylazides, benzophenone, diaryldiazomethane,aryltrifluoromethyldiazomethane, and organoboron, at least one sidechain D1 is a hexyl-amine, at least one side chain D2 is PEG, the sidechains E include at least one amino propyldimethyl ethoxy silane and atleast one nitrodopamine, and side chain D3 is optionally amine PEGbiotin or amine PEG NTA.
 9. Functional polymer according to claim 8,wherein the polymer backbone before carrying out a modification reactionis a polymer strand comprising reactive groups G selected from the groupconsisting of esters, activated esters, chloro, fluoro, acrylates,methacrylates, NHS esters, epoxides, anhydrides, azides, alkines, andacyltrifluoroborates.
 10. A method comprising coating the functionalpolymer according to claim 8 in a monomolecular layer having a thicknessof 0.1 to 10 nanometers, or coating the functional polymer according toclaim 8 in a multilayered system having a thickness of 10 nanometer to10 micrometers.
 11. A method comprising applying a functional polymeraccording to claim 8 as coating of a substrate selected from the groupconsisting of metal oxides, noble metal surfaces, and polymers.
 12. Amethod comprising applying a functional polymer according to claim 8 asanti-fouling coatings or as multi-functional coatings.
 13. Functionalpolymer having the formula

wherein A is a monosubstituted alkylene or arylene group, B is an amide,an ester or an ether group and n is either 0 or 1, F is selected fromthe group of an ester, a secondary amine, an amide, an ether, a thioether, a thio ester, and may be the same or different for the differenttypes of side chains, D is a side chain which is intended to reversiblebind to a substrate or has a coating function, and D is selected fromthe group consisting of: a short chain side chain D1 having a linear orbranched, substituted or unsubstituted C₁ to C₁₂ alkyl group R_(D1)which optionally comprises heteroatoms and which carries at least onefunctional group K1; a side chain D2 having a long chain R_(D2) having amolecular weight of at least 500 Da and selected from the groupconsisting of polydimethylsiloxane, perfluoroethers, perfluoroalkyls,polyisobutene, polyethylene glycol, polydimethylacrylamide,polyvinylpyrrolidone, polyalkyloxazolines, dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-(hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide),whereby D2 has no functional end group or side group K1, K3 or K4; and aside chain D3 having a long chain R_(D3) having a molecular weight of atleast 500 Da and selected from the group consisting of apolydimethylsiloxane, perfluoroethers, perfluoroalkyls, polyisobutene,polyethylene glycol, polydimethylacrylamide, polyvinylpyrrolidone,polyalkyloxazolines, dextran, carboxymethyl dextran,poly(N-isopropylacrylamide), poly(N-hydroxyethylacrylamide,poly(2-hydroxyethyl methacrylate), poly-(hydroxypropylmethacrylate),poly-(methacryloyloxylethyl phosphorylcholine), poly-(sulfobetainemethacrylate), polyalkylene residues having more than 20 carbon atoms,peptide chains, DNA fragments and poly-(sulfobetaine acrylamide) wherebyD3 carries at least one functional end or side group K3, E is a sidechain which is intended to irreversibly bind to a substrate, the sidechain E having either a linear or branched, substituted or unsubstitutedC₁ to C₂₀ alkyl group R_(E) which optionally comprises heteroatoms andcarries at least one functional end group K4, or is the functional endgroup K4, the polymer comprises 2 to 8 different types of side chains Dand 1 to 5 different types of side chains E, the polymer comprising aplurality of each type of side chain, whereby a post-modificationprocedure is used to sequentially add the different types of side groupsto a backbone of a polymer intermediate comprising reactive groups inorder to randomly or regularly distribute the different types of sidechains in the polymer, the polymer comprises (i) at least 1 type of sidechain D1, and (ii) at least 1 type of side chain D2 and/or at least 1type of side chain D3, the functional group K1 in side chain D1 isselected from the group consisting of amines, carboxy, poly (propylenesulfide), and thioethers, the functional group K3 in side chain D3 isselected from the group consisting of amines, carboxy, fluorescencemarkers, antibodies, biotin, nitrilotriacetic acid (NTA), peptides, anda single stranded DNA fragment, the functional group K4 in side chain Eis selected from the group consisting of alkoxy silanes, chloro silanes,nitrocatechol, phosphates, phosphonates, mimosine derivatives,anacheline, gallols, thiols, N-heterocyclic carbenes, perfluorophenylazides, benzophenone, diaryldiazomethane,aryltrifluoromethyldiazomethane, and organoboron, the polymer has theformula:

where n is 11 to 230, and the five different types of side chains may beregularly or randomly distributed.
 14. A method comprising coating thefunctional polymer according to claim 13 in a monomolecular layer havinga thickness of 0.1 to 10 nanometers, or coating the functional polymeraccording to claim 13 in a multilayered system having a thickness of 10nanometer to 10 micrometers.
 15. A method comprising applying afunctional polymer according to claim 13 as coating of a substrateselected from the group consisting of metal oxides, noble metalsurfaces, and polymers.
 16. A method comprising applying a functionalpolymer according to claim 13 as anti-fouling coatings or asmulti-functional coatings.